package com.zwh;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class POIUtil {
	private final static String xls = "xls";
	private final static String xlsx = "xlsx";

	/**
	 * 读入excel文件，解析后返回
	 * 读取除第一行外的所有行
	 * @param file
	 * @throws IOException 
	 */
	public static List<String[]> readExcel(File file) throws IOException {
		//检查文件
		try {
			checkFile(file);
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
		//获得Workbook工作薄对象
		HashMap<String, Object> res = getWorkBook(file);
		Workbook workbook = (Workbook) res.get("workbook");
		InputStream iStream = (InputStream) res.get("fileInputStream");
		//创建返回对象，把每行中的值作为一个数组，所有行作为一个集合返回
    	List<String[]> list = new ArrayList<String[]>();
    	if(workbook != null){
    		for(int sheetNum = 0;sheetNum < workbook.getNumberOfSheets();sheetNum++){
    			//获得当前sheet工作表
        		Sheet sheet = workbook.getSheetAt(sheetNum);
        		if(sheet == null){
        			continue;
        		}
        		//获得当前sheet的开始行
        		int firstRowNum  = sheet.getFirstRowNum();
        		//获得当前sheet的结束行
        		int lastRowNum = sheet.getLastRowNum();
        		//循环除了第一行的所有行
        		for(int rowNum = firstRowNum+1;rowNum <= lastRowNum;rowNum++){
        			//获得当前行
        			Row row = sheet.getRow(rowNum);
        			if(row == null){
        				continue;
        			}
        			//获得当前行的开始列
        			int firstCellNum = row.getFirstCellNum();
        			//获得当前行的列数
        			int lastCellNum = row.getPhysicalNumberOfCells();
        			String[] cells = new String[row.getPhysicalNumberOfCells()];
        			//循环当前行
        			for(int cellNum = firstCellNum; cellNum < lastCellNum;cellNum++){
        				Cell cell = row.getCell(cellNum);
                        cells[cellNum] = getCellValue(cell);
        			}
        			list.add(cells);
        		}
    		}
    		workbook.close();
    		iStream.close();
    	}
		return list;

	}



	private static HashMap<String, Object> getWorkBook(File file) {
		//获得文件名
		String fileName = file.getName();
		//创建Workbook工作薄对象，表示整个excel
		Workbook workbook = null;
		InputStream is = null;
		try {
			//获取excel文件的io流
			is = new FileInputStream(file);
			//根据文件后缀名不同(xls和xlsx)获得不同的Workbook实现类对象
			if (fileName.endsWith(xls)) {
				//2003
				workbook = new HSSFWorkbook(is);
			} else if (fileName.endsWith(xlsx)) {
				//2007
				workbook = new XSSFWorkbook(is);
			}
		} catch (IOException e) {
			//logger.info(e.getMessage());
			e.printStackTrace();
		}
		HashMap<String, Object> res = new HashMap<String, Object>();
		res.put("workbook", workbook);
		res.put("fileInputStream", is);
		return res;
	}

	private static void checkFile(File file) throws IOException {
		//判断文件是否存在
		if (null == file) {
			//logger.error("文件不存在！");
			throw new FileNotFoundException("文件不存在！");
		}
		//获得文件名
		String fileName = file.getName();
		//判断文件是否是excel文件
		if (!fileName.endsWith(xls) && !fileName.endsWith(xlsx)) {
			//logger.error(fileName + "不是excel文件");
			throw new IOException(fileName + "不是excel文件");
		}
	}
	
	public static String getCellValue(Cell cell){
		String cellValue = "";
		if(cell == null){
			return cellValue;
		}
		//把数字当成String来读，避免出现1读成1.0的情况
		if(cell.getCellType() == Cell.CELL_TYPE_NUMERIC){
			cell.setCellType(Cell.CELL_TYPE_STRING);
		}
		//判断数据的类型
        switch (cell.getCellType()){
	        case Cell.CELL_TYPE_NUMERIC: //数字
	            cellValue = String.valueOf(cell.getNumericCellValue());
	            break;
	        case Cell.CELL_TYPE_STRING: //字符串
	            cellValue = String.valueOf(cell.getStringCellValue());
	            break;
	        case Cell.CELL_TYPE_BOOLEAN: //Boolean
	            cellValue = String.valueOf(cell.getBooleanCellValue());
	            break;
	        case Cell.CELL_TYPE_FORMULA: //公式
	            cellValue = String.valueOf(cell.getCellFormula());
	            break;
	        case Cell.CELL_TYPE_BLANK: //空值 
	            cellValue = "";
	            break;
	        case Cell.CELL_TYPE_ERROR: //故障
	            cellValue = "非法字符";
	            break;
	        default:
	            cellValue = "未知类型";
	            break;
        }
		return cellValue;
	}
}
